Relative to the present invention, there are two general types of cleaning compositions presently available on the market; those that are strongly acidic and those that are strongly alkaline. Both types of products are irritating to the skin. In terms of usage, they are not particularly effective in removing lime soap and hard water salt deposits from hard surfaces such as ceramic tile, porcelain and fiberglass sinks, tubs, and shower enclosures. Their foaming characteristics are such that they drain rapidly on vertical surfaces. A product that combines the features of safety, efficacy and performance in removing lime soap and hard water deposits has, heretofore, not been available.
In order to clean lime soap and hard water deposits from bathtubs, shower stalls, sinks, bathroom tile and fixtures, the houseperson has had to resort to the use of scouring powders. These cleaners are abrasive and, over a period of time, will scratch even a porcelain sink or ceramic tile. They are very deleterious on plastic tile, plastic fixtures, fiberglass tubs and sinks, and tile group. Extensive rinsing is required to remove the cleaner powder residues from the substrate. The common anionic and nonionic detergents on the market today are not effective in performing the cleaning operations defined above. They do not remove the residues in question.
It is appreciated that there are no standard tests that are generally accepted for the evaluation of such cleaning compositions. The laboratory tests described in this specification were designed to be as close to actual use conditions as possible. Of particular import in this regard is effectiveness of lime soap and hard water salt removal, safety of use, foam stability and biodegradability. These requirements are all met with compositions of the applicant's invention as will be subsequently described.
As far as safety is concerned, one product currently available on the market, and which represents the state-of-the-art, is Scrub Free (Economics Laboratory, Inc., St. Paul, Minn.). This is a strongly acidic solution of about pH 1.5. It is dispensed as a spray foam. Scrub Free contains sulfamic and hydroxyacetic acids which are described as hazardous materials in the manufacturer's safety data sheets (E. I. duPont de Nemours and Co., Wilmington, Del.). Both acids cause eye burns and contact with the skin is to be avoided.
A second product is Tough Act, a heavy duty bathroom cleaner, marketed by the Dow Chemical Co. (Midland, Mich.). It is representative of the strongly alkaline cleaners, possessing a pH of 11.5. As such, contact with the skin and eyes should be avoided. Two other alkaline cleaners being sold are Fantastik (Texite Chemicals Co., Greenville, S. C.) and Formula 409 (Clorox Co., Oakland, Calif.). In the manufacturers' directions they are recommended for use on tubs, showers, basins and ceramic tile. Both products possess a pH in excess of 11 and they rely on their strongly alkaline properties for cleaning. The warning on the Fantastik label states that the product is not to be used on glass. Formula 409 is not recommended for use on aluminum. The alkalinity of Fantastik and Formula 409 makes them strong eye irritants. In applying the tests used in evaluating the compositions of applicant's invention, it was found that Fantastik and Formula 409 did not remove lime soap or hard water salt deposits.
As far as efficacy is concerned, the cleaners, Scrub Free and Tough Act, rely on their extremely acidic and alkaline character, respectively, for the removal of soap scum, hard water deposits and dirt. They are not effective in the more neutral pH ranges. In fact, it has been found that both products are only partially effective in removing lime soap and hard water deposits in the tests used in evaluating applicant's compositions.
It is a further disadvantage of the aforementioned four products that they attack and corrode many of the surfaces found in bathrooms. The acidic product, Scrub Free, attacks marble and aluminum. In fact, the manufacturer's label contains a warning that Scrub Free should not be used on such surfaces. Alkaline solutions are known to corrode aluminum and Fantastik, Formula 409 and Tough Act, would be expected to do the same.
The compositions of the present invention do not suffer from such deficiencies and, as such, offer a wider spectrum of usage. The cleaning of marble tile and aluminum shower enclosures is not a problem with compositions of the invention.